Speed-gear for motors.



PATENTED AUG. 25, 1903.

A. BLHOLSON. SPEED GEAR FOR MOTORS.

APPLICATION FILED JAN. 6, 1902.

2 SHEETS-SHEET 1.

H0 MODEL.

vZizUenipr' 7 'PATBNTED AUG. 25, 1903.

7 A. B. HOLsON. SPEED GEAR FOR MOTORS.

APPLICATION FILED JAN. 6, 1902.

2 SHEETS-SHEET 2.

K0 MODEL.

' Patented August 25, 1902.

i PATENT OFFICE.

ALBERT B. 'IIOLSON, OF yOHICAGO, ILLINOIS.

s P -EED-G EAR F'o R MFO'TORS.

SPECIFICATION forming part of Letters Patent No. 737,237, dated August 25, 1903.

Application filed January 6, 1902. Serial No. 88l621l N l-l To (all whom, it nut concern:

Be-it known that I, ALBERT B. HOLSON, a resident of Chicago, Cook county, Illinois, have invented certain new and useful Improvements in Speed-Gear for Motors,of whicli the following is a specification. This invention relates to improvements in speed-gears for electrical motors, and has reference more particularlyt'o an improved construction in speed-gears particularly applicable to motors of that general type set forthin my previous application for Letters Patent; Serial No. 68,374, filed July 15, 1901.

Among the salient objects of the present invention are to provide a construction and arrangement whereby the speed imparted to a driven member actuated by the armature of the motor may be Varied by simply looking diiferent concentrically-disposed annular racks with the driving-pinions of the motor and Without rearranging any of the parts; to provide in a construction of this general character improved means of conveniently throwing the various driving connections into and out of gear; to provide simple and improved details of construction, enabling the parts to be adjusted to compensate for wear and to be readily taken apart and reassembled; to provide improved details of construction contributing to the ease of running and dnrability of the mechanism, and in general to pro"- vide a simple and improved construction of the character referred to.

To these ends the invention consists in the matters hereinafter described, and more par ticularly' pointed out in the appended claims, and the same will be readily understood from the description, reference being had to the accompanying drawings, in which- Figure 1 is an axial sectional View of the armature-casing and driving-racks therein, the armature, its support, and its pinions being shown in elevation. Fig. 2 is a fragmentary view of a portion of Fig. l on a larger scale. Fig. 3 is a fragmentary view in edge elevation of a rotatable outer member or casing, showing particularly the manner of adjustably uniting the two halves of said casing. Fig. 4 is a sectional view taken on line at 4 of Fig. 3. Fig. 5 is fragmentary plan vieW of a portion of the casing which overlies the annular driving-racks, showing particularly the locking-key and the key-aperture. Fig.

' 6 is a perspective view of one of said lockingkeys. Fig. 7 is a fragm'entary plan view taken in the plane of the meeting surfaces of the two-part annular racksas, for example, on line 7 f Fig. 1 and showing particularly the disposition of the antifriction-balls therein, Fig. S'is a view of the inner armature support or casing, particularly in end elevation and partly broken away to expose the armature therein. Fig. 9 is a view of the parts shown in Fig. 8, partly in side elevation andpartly broken away to expose the construction andarrangement of the armato re. Fig. 10 is a fragmentary sectional view taken on line l0 10 of Fig. 2.

While the present embodiment of the invention shows an armature constructed and arranged substantially in accordance with that set forth in my previous application,

hereinbefore referred to, nevertheless it is to he understood that the particular details of construction of the motor are not essential to the carrying out of the invention, although the invention is particularly applicable to that type of motors. With this explanation in ViewIwilldescribethepreferred embodiment, illustrated in the drawings, in which- 10 designates as a whole an outershell-like member or casing, which in this instance constitutes the rotary driven member of the n10- tor or that member to which a differential rate of movement is imparted from the inclosed motor through the medium of the speedgearing constituting the salient feature of the invention. In the present instance said outer driven member is made in the form of an approximately spherical or globe-like shell arranged to inclose both the armature of the motor and the commutator mechanism thereof. At diametrically opposite points said outer shell is provided with journal portions 12 and 12', respectively, which are journaled upon the trunnion-like journal portions 14 and 15, respectively, of an inner stationary member designated as a whole 13, hearing rings 16 and 16 being preferably interposed between said bearing members.

The stationary member 13 comprises a ringlike frame or annnlus.17, externally semispherical, so as to fit closely within the outer shell and provided at each side with closing cap members 18 and 18, which, together with said annular member, form a substantially complete inner casing, which is rigidly supported and within which is rotatably mounted the armature proper 11. The end caps 18 and 18' are removably attached to the stationary ring member 17, conveniently by means of tap-bolts, as indicated at 20.

The armature 11 may be of any suitable type, that shown herein being externally cylindric, while the field-pieces 21, which are rigidly supported upon the interior of the stationary ring 17 at regular intervals apart, as best shown in Fig. 8, are correspondingly hollowed at their inner sides, as indicated at 22, to approach as nearly as possible the periphery of the armature without interfering with the movement of the latter. In the present instance there are four such field-pieces, which are accordingly arranged at ninety degrees apart.

24 designates as a whole the main shaft of the armature, which is provided at each end with hearing portions, as 23, which extend within bearing-apertures 25, formed directly through the end walls or caps 18 18 of the inner motor-casing, also as best indicated in Figs. 8 and 9, the armature-shaft being arranged to extend at each of its ends through and beyond said end caps and being provided at its extremities with elongated driving-pinions, respectively designated 26 and 26, which pinions are arranged to engage with annular racks or driven members 27 28 29 and 27, 28, and 29. In this connection it is to be observed that the axis of the main shaft of the motor is arranged in such relation to the journal portions of the outer rotatable casing or driven member as to extend transversely across the interior of said outer casing or shell nearly at right angles to the axis of rotation of the shell, but inclined suffieiently from a right angle to cause the driving-pinions 26 and 26 of the shaft to respectively engage the two sets of racks or driven members at diametrically opposite points, notwithstanding such racks are separated from each othera distance somewhat greater than the largest diameter of the pinions, as indicated clearlyin Fig. 1. Inasmuch as the outer rotary shell is journaled upon the fixed member 13 and the armature is journaled within said fixed member it will be obvious that the armatu re-shaft is maintained in fixed relation to the shell and driven racks carried thereby, the outer casing being free to rotate under the driving movement of the armature. In order to support the two sets of annular racks, the outer shell or casing is formed with a circumferential enlargement or extension arranged at right angles to the axis of rotation of such'shell and in a plane passing through the center of the armature, thereby forming an annular extension or enlargement approximately rectangular in cross-section, within which several annular racks are mounted, as now to be described. In the preferred embodiment shown herein the several racks are made of approximately equal size in cross-section and arranged to rest contignous to and concentric with each other, the three concentrically-arranged racks of each oppositely-disposed set together occupying a rectangular groove or seat, as 30 and 30, formed in the opposed halves of the outer shell. The respective pinions 26 and 26 are are arranged to mesh simultaneously with all three of the racks at each end, and the pinions are therefore made conical to the extent necessary to compensate for the inclination of the main shaft from the plane of the sets of racks, so as to intermesh properly and to the full depth of the rack and pinion teeth in the case of each of the several racks.

It will be observed from the foregoing description that as the armature rotates the several racks will be simultaneously driven,

but with a differential rate of movement, de-

pending upon the different radial distances from the center of the armature or, in other words, depending upon the circumferential length of the several racks. Obviously, therefore, if any given pair of oppositely-disposed racks be locked rigid with the outer casing and the remaining racks of the set be free to rotate within the casing the rate of movement imparted to the outer shell by the armature will depend upon the relation of the rigid rack to the center of the armature, the outermost rack obviously imparting the slowest movement and the innermost the most rapid movement. As a convenient means of thus locking the racks rigid with the outer I casing I provide pairs of keys, as 31 and 31, adapted to be inserted through keyholes 32 in the respective side walls of the casing and into corresponding recesses or apertures 33, formed in the subadjacent racks. As a convenient means of locking said keys in engaging position each is provided with a lug or bit-like extension 31, adapted to pass through the slot-like extension 32 of the keyhole in the casing and to be rotated into engagement with a suitable undercut recess 35, formed in the inner side of the casing, thereby locking the key positively against retraction until it has been rotated into position to register with the slot 32. Preferably the keyholes 32, which are provided for each rack-section, and the recesses in the latter are made of uniform size and shape, so that the keys 31 and 31 may be used interchangeably to lock any given pair of racks rigid with the casing.

Inasmuch as all of the racks are constantly in mesh with the respective pinions those racks which are not acting as the driving connections between the pinions and casing necessarily have a rotative movement relatively to the casing within which they are mounted, and relatively to each other and to the rigid rack. In order to reduce to a minimum the friction incident to this movement, I preferably provide antifriction-rollers, which ICO are conveniently and desirably arranged as follows: In order to support the outer-face sides of the annular racks and prevent them from resting directly against the seats 30 and 30, formed in the rotary casing, I provide each of said racks upon its saidouter surface with an annular groove or ball-race 36, and-in register-with these several grooves 36 I provide a similar short groove or cavity 37 in the overlying casing. (See particularly Fig. 8.) Preferably I provide a plurality of these recesses 37 at intervals apart around the circumference of the rack-ring, each adapted to contain a plurality of balls side by side as, fol-example, a group of threethe depth of the grooves or recesses 37 being approximately one-half the diameter of the balls, so that the latter will be confined against traveling with the rack-rings. The depth of the grooves or recesses in the rack-rings is such as to support said rings free from direct bearing with the seat against which theylie. In order to minimize the friction between the rings themselves and between the outermost ring and the casing, I provide other sets of antifriction-balls, which are interposed between the meeting surfaces of the rack-rings of each set and between the outermost rackring and the overlying side wall of the casing. Preferably, I provide the outer peripheral surface of the'rack-ring with a circumferential groove or race, as 38, and in the approximate or inner surface of the contiguous ring I provide short grooves or recesses 39, generally similar to the recesses 37, hereinbefore described, as shown clearly in Fig. 7. In the case of the outermost rack-rings, these recesses 39 are formed in the inner side wall of the rotary casing, which is opposed to the peripheral surface of the outer ring. In order to enable the several groups of balls to be placed between the several racks, I make each of said racks of two-part construction, dividing the rack in the plane of its ball-race 38, as indicated at 40, and secure these racksections together after the balls have been properly assembled in place by means of suit able balls or screws 41. In the case of the outermost sets of rollers, which are interposed between the outer peripheries of the two outermost rack-rings and the overlying casing, I provide apertures or filling-holes42,arranged to extend radially in through the casing to the pockets 39, through which the balls may be inserted, these filling-apertures being severally closed by means of screw-plugs 43, as shown clearly in Figs. 2 and 7.

In order to detachably unite the two members of the outer casingin a plane extending between the opposed sets of rack-rings, I construct one member so as to telescope upon or overlap the opposite member, as indicated at 44, and provide in the overlapping portion 44 V a plurality of transverse]y-extending slots 45,

(see Fig. 3,) through'which are inserted setscrews 45, which are threaded at'their inner ends into the underlying portion 46 of the meeting casing member. By means of this construction I am obviously enabled to telescope the casing members together to the exact extent necessary to insure the proper interm eshing of the pinions with the respective sets of rack-rings, and I may obviously change this adjustment from time to time to compensate for wear of the pinions and other movable parts/ The driving power may be taken from the outer rotary casing in any preferred manner-as, for example, in the present instance I contemplate applying a belt directly to the peripheral portion 44 of the casing, and to this end the latter is made slightly crowning in cross-section and is extended approximately the full width of the extension portion of both members of the casing. be understood, however, that the construc tion may be modified and the power taken from the rotary casing otherwise than by means of a belt. In the case of a belt-drive the trunnion-like extensions 47 of the rigid inner frame member 13 maybe conveniently secured rigidly in suitable frame members 48, said extensions 47 being shown in the present instance as being secured by means of said screws 49.

As hereinbefore stated, the specific construction of the armature which constitutes the driving element of the mechanism may be varied within the scope of the invention, the construction and arrangement of that shown herein being as follows: The extended ends of the armature-shaft between the pinions and armature proper and outside of the end caps or walls of the inner motor-shell are inclosed in extensions or housings 50, (see Figs. 8 and 9,) which are internally enlarged at the lower sides of the shaft to form oilcups 51, adapted to contain supplies of oil. In order to convey a continuous supply of oil from said oil-cups to the shaft of themmature, rings 52 are mounted loosely upon said shaft, which are of larger diameter than the shaft and are arranged to depend within the respective oil-cups, the rotation of the shaft serving to rotate the rings, and thus carry a continuous supply of oil forwardly to the shaft. These rings are suitably spaced apart by means of collars 51 and 51. Upon the armature-shaft, at a point inside of one of the end caps, is mounted a commutator 55, composed ofa plurality of segments,insulated from each other and from the shaft in the usual manner and which segments are severally connected with the windings of the armature. The commutatorbrushes 53 are mounted upon the end cap member 18 adjacent to the commutator, so as to be removable with said cap. To this end 54 and 54 designate fixed studs mounted to project on the interior of said end cap, in the present instance at points separate from each other an angular distance of ninety degrees, and upon the inner ends of said studs are mounted:

These brush-holders in brush-holders 56.

It will ICC the preferred embodiment shown consist simply of fixed guides or sockets arranged to extend approximately tangential to the commutator-hub and within which are arranged to slide commutator blocks or brushes 53, which are desirably of carbon and hear at theirinnerends against the commutator-hub. Said brushes are held yieldingly in contact with the commutator by means of springs 57, working through suitable slots 58, formed in the brush-holders, as indicated clearly in the drawings. The conductors 50 and 50', connecting the motor with any suitable source of current, are respectively connected with the studs 54 and 54' and extend thence out through a passage 59, formed to extend axially through the upper journal portion of the inner motor-shell or fixed member, as seen clearly in Fig. 9. Another pair of conductors60 and 60 is arranged to supply current to the field-windings of the motor, these con ductors being likewise arranged to extend out through the passage 59. Openings 61 are desirably provided in each of the end cap members 18 and 18, both for the purposes of inspection and air circulation.

The operation of the motor has been clearly indicated in connection with the foregoing description and need not, therefore, be repeated.

In describing the present invention I have used the terms racks and pinions in describing the driving connections between the motor proper and the gear-rings; but I wish to be understood as using the terms racks and pinions generically and that in the broader sense of the invention frictionally-driven rings acted upon by friction gear members instead of pinions are the equivalents of the rack-and-gear connections described and shown herein.

I claim as my invention-- 1. -In a variable-speed-gear mechanism, the combination with a suitable frame-support, of a rotary motor element journaled therein, provided with a gear member arranged concentric with the axis of rotation of said motor element and a plurality of annular gear members arranged concentrically with each other and around said motor element and severally operatively engaged with the gear mem= ber thereof.

2. In avariable-speed-gear mechanism, the combination with a suitable frame-support of a rotary motor element journaled therein provided with axial extensions at each side carrying gear members, and a plurality of annular gear members arranged concentrically with each other and severally operatively engaged with the gear members of the motor.

3. Inavariable-speed-gear mechanism, the combination with a suitable frame-support, of a rotary motor element journaled in said' support, provided at each side with axial extensions having gear members thereon, two sets of annular gear members arranged in parallel relation to each other, each set com-' prising a plurality of annular gear members arranged concentric with each other and severally operatively engaged with one of the gear members of the motor element, the members of each set being engaged with the respective gear members of the motor element, and in diametrically opposite relation to each other.

4. Inavariable-speed-gear mechanism, the combination with a suitable frame-support, of a rotary motor element journaled in said frame and provided with axial extensions at each side carrying gear members, a driven member arranged around said motor element and journaled to rotate upon an axis transverse to the axis of rotation of the motor element and means for imparting rotation from the motor element to said driven member comprising two sets of annular gear members movably mounted within said driven member, and adapted to be locked rigid therewith, each of said sets comprising a plurality of annular members arranged concentrically with each other and severally engaged with one of the gear members of the motor, the members of the respective sets being engaged with the opposite geai' members of the motor element and in diametrically opposite relation to each other, substantially as described.

5. In avariable-speed-gear mechanism, the combination with asuitable stationary hollow frame of a motor journaled to rotate therein, and provided with axial extensions having gear-pinions thereon, an outer frame journaled to rotate upon and inclosing said stationary frame, two sets of annular gear members movably mounted within said rotatable frame in parallel relation to each other, each set comprising a plurality of annular gear members arranged concentrically with each other and surrounding said motor and severally operatively engaged with one of the pinions of the motor, the members of the two sets being respectively engaged with theopposite pinions of the motor, and means for locking any given pair of annular gear members rigid with said rotary outer frame, sub stantially as described.

6. Inavariable-speed-gear mechanism, the combination with a stationary hollow frame and a series of field-magnets upon its interior, of a motor journaled to rotate therein and provided with axial extensions having gearpinions thereon, commutator-brushes mounted upon said stationary frame, a commutator mechanism with which said brush es cooperate mounted upon the armature of the motor, an outer frame journaled to rotate upon and substantially inclosing said stationary frame, the axis of rotation of the outer frame being arranged transversely with relation to the axis of rotation of the armature, two sets of within said rotatable frame and in parallel IOC IIC

relation to each other, each set comprising a plurality of annular racks arranged concentrically with each other, and to extend around said motor and severally and operatively engaged with one of the pinions of the motor, the members of the two sets being respectively engaged with the opposite pinions of the motor, means for locking any given pair of oppositely-disposed rack members rigid with said outer rotary frame, and suitable electrical connections, substantially as described.

7. In a variablespeedgear mechanism, the combination with a stationary hollow frame provided at diametrically opposite points with trunnion-like extensions, of a motor journaled to rotate therein upon an axis transverse to the axis of the'trunnion-like extensions and provided at its opposite sides with axial extensions carrying elongated pinions, an outer frame journaled upon the trunnion-like extensions of the stationary frame and inclosing the latter, annular rack-seats formed in said outer casing and arranged in a plane at right angles to the axis of rotation of the casing, two sets of annular gear-racks mounted Within said rack-seats and arranged with their toothed surfaces facing each other and separated a distance greater than the diameter of the pinions of the motor, each set of racks consisting of two or more rackrings arranged concentrically with each other and severally engaged with one of the pinions of the motor, the opposite sets of racks being arranged to respectively engage the opposite pinions of the motor at diametrically opposite points, and means for locking said racks individually rigid with the outer casing, substantially as described.

8. In a variable-speed-gear mechanism, the combination with a stationary hollow frame provided at diametrically opposite points with trunnion-like extensions, of a motor journaled to rotate therein upon an axis transverse to the axis of the trunnion-like extensions and provided atits opposite sides With axial extensions carrying elongated pinions, an outer frame journaled upon the trunnion-like extensions of the stationary frame and inclosing the latter, annular rack-seats formed in said outer casing and arranged in a plane at right angles to the axis of rotation of the casing, two sets of annular gear-racks mounted within said rack-seats and arranged with their toothed surfaces facing each other and separated a distance greater than the diameter of the pinions of the motor, each set of racks consisting of two or more racks arranged-concentrically with each other and severally engaged with one of the pinions of the motor, the opposite sets of racks being arranged to respectively engage the opposite pinions of the motor at diametrically opposite points, means for locking said racks individually rigid with the outer casing, and antifriction devices interposed between said racks and their respective seats, substantially as described.

9. Ina variable-speed-gear mechanism, the combination with a stationary hollow frame provided at diametrically opposite points with trunnion-like extensions,of a motor journaled to rotate therein upon an axis transverse to the axis of the trunnion-like extensions and providedat its opposite sides with axial extensions carrying elongated pinions, an outer frame journaled upon the trunnionlike extensions of the stationary frame and inclosing the latter, annular rack-seats formed in said outer casing and arranged in a plane at right angles to the axis of rotation of the casing, two sets of annular gear-racks mounted within said rack-seats and arranged with their toothed surfaces facing each other and separated a distance greater than the diameter of the pinions of the motor, each set of racks consisting of two or more rack-rings arranged concentrically with each other and severally engaged with one of the pinions of the motor, the opposite sets of racks being arranged to respectively engage the opposite pinions of the motor at diametrically opposite points, means for locking said racks individually rigid with the outer casing, and antifriction devices interposed between said several racks and their seats and between the contiguous edges of the racks, substantially as described.

10. In an invariable-speed-gear mechanism, the combination with an inner stationary shell and an armature journaled therein and provided with pinions at each end of its main shaft, of an outer inclosi'ng shell of twopart construction journaled to rotate upon said stationary frame and provided upon its interior with a plurality of facing annular racks between which the pinions of the m0- tor areinterposed,said casing beiugconstructed to separate in a plane extending between the opposed racks and one member of said casing being arranged to telescope upon the other, substantially as described.

11. In a variable-speed-gear mechanism, the combination of an interior stationary shell and an armature journaled therein and provided with pinions at each end of its main shaft, of an outer inolosing shell of two-part construction journaled to rotate upon said stationary frame and provided upon its interior with a plurality of facing annular racks between which the pinions of the motor are interposed, said casing being constructed to separate in a plane extending between the opposing racks, and one member of said casing being arranged to telescope upon the other and being adjustably secured thereto, substantially as described.

ALBERT B. HOLSON.

Witnesses:

ALBERT H. GRAVES, Fnnnnnrox C. GooDwIN.

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